A surface printing method for PVC rubber inflatable balls

Abstract

The application discloses a surface printing method of a PVC rubber inflatable ball, and the method comprises the following steps: inflating a PVC inflatable ball blank to a first preset diameter, and placing the PVC inflatable ball blank on the inner side of a target first half-sphere printing film; inflating the PVC inflatable ball blank again, so that the PVC inflatable ball blank is tightly attached to the first inner wall of the target first half-sphere printing film; after the glue is solidified, the target first half-sphere printing film is peeled off from the surface of the PVC inflatable ball blank; inflating the target PVC inflatable ball blank to a second preset diameter, and placing the target PVC inflatable ball blank in a second half-sphere mold, so that the target PVC inflatable ball blank is located on the inner side of a target second half-sphere printing film; inflating the target PVC inflatable ball blank again, so that the target PVC inflatable ball blank is tightly attached to the second inner wall of the target second half-sphere printing film; and after the glue is solidified, the target second half-sphere printing film is peeled off from the surface of the target PVC inflatable ball blank, so that the surface printing effect is improved.

Description

Technical Field

[0001] This application relates to the field of curved surface printing technology, and more specifically, to a surface printing method for PVC rubber inflatable balls, which can be a step-by-step transfer printing method suitable for PVC (polyvinyl chloride) inflatable balls. Background Technology

[0002] Currently, the surface decoration of PVC rubber inflatable balls (such as advertising balls, toy balls, sports balls, etc.) traditionally uses screen printing or heat transfer printing technology. However, due to the soft spherical curved surface of the ball, direct printing usually has the following defects: 1. The pattern is easily deformed and the color registration is inaccurate at the curved stretching parts; 2. It is difficult to achieve high-precision, multi-color or gradient complex pattern printing; 3. Traditional heat transfer or water transfer printing processes often cause the ink layer to crack due to secondary stretching of the ball surface, or the misalignment of the hemispherical pattern seam due to inaccurate positioning, resulting in a low yield rate.

[0003] Therefore, the problem of how to improve the surface printing effect of PVC rubber inflatable balls urgently needs to be solved. Summary of the Invention

[0004] This application provides a surface printing method for PVC rubber inflatable balls, which can improve the surface printing effect of PVC rubber inflatable balls.

[0005] This application provides a surface printing method for a PVC rubber inflatable ball, the method comprising: The pre-designed graphics are reverse-printed onto a thermoplastic plastic transfer film to obtain the target plastic transfer film. A first hemispherical printing film and a second hemispherical printing film are generated based on the target plastic transfer film; Adhesive is applied to the inner surfaces of the first hemispherical printed film and the second hemispherical printed film respectively to obtain the target first hemispherical printed film and the target second hemispherical printed film. A first hemispherical mold matching the target first hemispherical printing film is provided, and a second hemispherical mold matching the target second hemispherical printing film is provided; The target first hemisphere printed film is placed into the first hemisphere mold; Inflate the PVC inflatable balloon to a first preset diameter, place the PVC inflatable balloon inside the target first hemisphere printed film, and then inflate the PVC inflatable balloon a second time to make it expand and fit tightly against the first inner wall of the target first hemisphere printed film. The target first hemisphere printed film is peeled off from the surface of the PVC inflatable ball blank after the adhesive has cured and the glue remains in a fixed position on the first inner wall for a first preset time. Place the target second hemisphere printed film inside the second hemisphere mold; The target PVC inflatable blank is inflated to the second preset diameter, and then the target PVC inflatable blank is transferred into the second hemispherical mold, so that it is located inside the target second hemispherical printing film. It is then inflated a second time, so that the target PVC inflatable blank expands and fits tightly against the second inner wall of the target second hemispherical printing film. After the adhesive has cured, the target second hemisphere printing film is peeled off from the surface of the target PVC inflatable ball blank, thus obtaining a transfer of all the graphics and text onto the surface of the PVC rubber ball blank.

[0006] Implementing the embodiments of this application has the following beneficial effects: As can be seen, the surface printing method for PVC rubber inflatable balls described in this application simplifies the complex global curved surface problem into two relatively controllable local curved surface problems by pre-decomposing the preset graphic (the pattern to be printed) into two hemispherical printing films and using matching hemispherical molds for positioning and operation. The step-by-step processing (first the first hemisphere, then the second hemisphere) greatly reduces the difficulty of accurately positioning and attaching the pattern on the complete spherical surface at one time. Ultimately, it can achieve high precision, no deformation, no seams, and high accuracy requirements on the entire surface of the PVC inflatable ball blank, thereby improving the surface printing effect of the PVC rubber inflatable ball.

[0007] Furthermore, since the first hemisphere is printed first, followed by the second hemisphere, the image in the second hemisphere slightly overlaps the image in the first hemisphere by a predetermined length (this predetermined length can be an empirical value, such as 0.2mm). If both hemispheres are printed simultaneously, a seam will inevitably appear. However, printing the image in the first hemisphere first avoids this gap. For example, the image in the southern hemisphere can be printed first, followed by the image in the northern hemisphere, with the northern hemisphere image slightly overlapping the image in the southern hemisphere by 0.2mm. Again, if both hemispheres are printed simultaneously, a seam will inevitably appear. However, printing the image in the southern hemisphere first avoids this gap. Attached Figure Description

[0008] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0009] Figure 1This is a schematic flowchart of a surface printing method for a PVC rubber inflatable ball provided in an embodiment of this application; Figure 2 This is a first illustrative schematic diagram of a surface printing method for a PVC rubber inflatable ball provided in an embodiment of this application; Figure 3 This is a second illustrative schematic diagram of a surface printing method for a PVC rubber inflatable ball provided in the embodiments of this application; Figure 4 This is a third illustrative schematic diagram of a surface printing method for a PVC rubber inflatable ball provided in the embodiments of this application; Figure 5 This is a fourth illustrative diagram illustrating a surface printing method for a PVC rubber inflatable ball provided in this application embodiment; Figure 6 This is a fifth illustrative diagram illustrating a surface printing method for a PVC rubber inflatable ball provided in this application embodiment; Figure 7 This is a sixth illustrative diagram of a surface printing method for a PVC rubber inflatable ball provided in this application embodiment; Figure 8 This is a seventh illustrative diagram of a surface printing method for a PVC rubber inflatable ball provided in this application embodiment; Figure 9 This is the eighth illustrative diagram of a surface printing method for a PVC rubber inflatable ball provided in the embodiments of this application; Figure 10 This is the ninth demonstrative schematic diagram of a surface printing method for a PVC rubber inflatable ball provided in the embodiments of this application. Detailed Implementation

[0010] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0011] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or apparatuses.

[0012] It should be understood that the term "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document indicates that the preceding and following related objects are in an "or" relationship. In the embodiments of this application, "multiple" refers to two or more.

[0013] In the embodiments of this application, "at least one item" or its similar expression refers to any combination of these items, including any combination of a single item or a plurality of items. "One or more" means one or more, while "multiple" means two or more. For example, "at least one item" of a, b, or c can represent the following seven cases: a, b, c; a and b; a and c; b and c; a, b, and c. Each of a, b, and c can be an element or a set containing one or more elements.

[0014] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0015] The embodiments of this application will be described in detail below.

[0016] In the prior art, the surface decoration of PVC rubber inflatable balls (such as advertising balls, toy balls, sports balls, etc.) has traditionally adopted screen printing or heat transfer printing technology. However, due to the soft spherical curved surface of the ball, direct printing usually has the following defects: 1. The pattern is easily deformed and the color registration is inaccurate at the curved stretching parts; 2. It is difficult to achieve high-precision, multi-color or gradient complex pattern printing; 3. Traditional heat transfer or water transfer printing processes often cause ink layer cracking due to secondary stretching of the spherical surface, or misalignment at the seam of the hemispherical pattern due to inaccurate positioning, resulting in a low yield rate. In order to solve the defects in the prior art, this application provides a surface printing method for PVC rubber inflatable balls, which includes the following steps: The pre-designed graphics are reverse-printed onto a thermoplastic plastic transfer film to obtain the target plastic transfer film. A first hemispherical printing film and a second hemispherical printing film are generated based on the target plastic transfer film; Adhesive is applied to the inner surfaces of the first hemispherical printed film and the second hemispherical printed film respectively to obtain the target first hemispherical printed film and the target second hemispherical printed film. A first hemispherical mold matching the target first hemispherical printing film is provided, and a second hemispherical mold matching the target second hemispherical printing film is provided; The target first hemisphere printed film is placed into the first hemisphere mold; Inflate the PVC inflatable balloon to a first preset diameter, place the PVC inflatable balloon inside the target first hemisphere printed film, and then inflate the PVC inflatable balloon a second time to make it expand and fit tightly against the first inner wall of the target first hemisphere printed film. The target first hemisphere printed film is peeled off from the surface of the PVC inflatable ball blank after the adhesive has cured and the glue remains in a fixed position on the first inner wall for a first preset time. Place the target second hemisphere printed film inside the second hemisphere mold; The target PVC inflatable blank is inflated to the second preset diameter, and then the target PVC inflatable blank is transferred into the second hemispherical mold, so that it is located inside the target second hemispherical printing film. It is then inflated a second time, so that the target PVC inflatable blank expands and fits tightly against the second inner wall of the target second hemispherical printing film. After the adhesive has cured, the target second hemisphere printing film is peeled off from the surface of the target PVC inflatable ball blank, thus obtaining a transfer of all the graphics and text onto the surface of the PVC rubber ball blank.

[0017] In this embodiment, the preset graphic (the pattern to be printed) is pre-decomposed into two hemispherical printing films, and each is positioned and manipulated using a matching hemispherical mold. This simplifies the complex global surface problem into two relatively controllable local surface problems. The step-by-step processing (first the first hemisphere, then the second hemisphere) greatly reduces the difficulty of accurately positioning and attaching the pattern on the complete spherical surface at once. Ultimately, it can achieve high precision, no deformation, no seams, and high accuracy on the entire surface of the PVC inflatable ball blank, thereby improving the surface printing effect of the PVC rubber inflatable ball.

[0018] Compared with the prior art, the embodiments of this application can have the following significant advantages: 1. Eliminate surface distortion: By pre-forming the flat printed film into a hemispherical shape, the graphics are pre-deformed before lamination, avoiding pattern distortion caused by direct stretching on the spherical surface.

[0019] 2. Precise alignment: Two transfers are performed using an independent hemispherical mold. The physical positioning of the mold ensures that the two hemispherical patterns are precisely aligned at the equator of the sphere, eliminating misalignment.

[0020] 3. Strong adhesion: Through secondary inflation and pressurization, the printed film and the sphere are tightly bonded in the mold. Combined with surface coating pretreatment, the adhesion of the ink layer is significantly improved, making it less prone to peeling and cracking.

[0021] 4. Adaptable to complex printing: This method can carry high-precision images and text pre-printed by offset printing, gravure printing, etc., and can achieve complex full-color pattern printing that traditional screen printing cannot complete.

[0022] Please see Figure 1 , Figure 1 This is a schematic flowchart of a surface printing method for a PVC rubber inflatable ball provided in an embodiment of this application. As shown in the figure, the surface printing method for the PVC rubber inflatable ball includes: S101: The preset design text is reverse-printed onto a thermoplastic plastic transfer film to obtain the target plastic transfer film.

[0023] The preset design graphics can be set in advance or set by system default. For example, the preset design graphics can carry the graphic content that the user needs to transfer, such as the transfer graphics of a globe.

[0024] Specifically, the design can be reverse-printed onto a thermoplastic transfer film to obtain the target plastic transfer film, which can then support the design.

[0025] S102: Generate a first hemispherical printing film and a second hemispherical printing film based on the target plastic transfer film.

[0026] The target plastic transfer film, i.e. the plastic transfer film with printed graphics, can be used to generate a first hemispherical printing film and a second hemispherical printing film based on the target plastic transfer film using vacuum forming technology.

[0027] Optionally, the above steps, generating the first hemispherical printing film and the second hemispherical printing film based on the target plastic transfer film, can be implemented in the following manner: The target plastic transfer film is subjected to vacuum forming to deform it into a first hemispherical printing film and a second hemispherical printing film that match the preset hemispherical shape of the balloon to be printed.

[0028] Among them, the target plastic transfer film (the plastic transfer film with printed graphics) can be vacuum-formed to deform it into a first hemispherical printing film and a second hemispherical printing film that match the shape of the hemisphere of the balloon to be printed.

[0029] Optionally, the thermoforming temperature of the thermoforming process is controlled between 80℃ and 150℃.

[0030] The thermoforming temperature is controlled within a preset temperature range, which can be pre-set or set by system default. For example, the preset temperature range is 80℃~160℃, or 80℃~150℃, or 100℃~180℃.

[0031] S103: Apply adhesive to the inner surfaces of the first hemispherical printed film and the second hemispherical printed film respectively to obtain the target first hemispherical printed film and the target second hemispherical printed film.

[0032] In this process, adhesive is applied to the inner surfaces of the first and second hemispherical printed films after vacuum forming. Specifically, adhesive is applied to the inner surface of the first hemispherical printed film to obtain the target first hemispherical printed film, which is the first hemispherical printed film after adhesive is applied to its inner surface. Adhesive is then applied to the inner surface of the second hemispherical printed film to obtain the target second hemispherical printed film, which is the second hemispherical printed film after adhesive is applied to its inner surface.

[0033] Among them, environmentally friendly water-based adhesives can be used, which can extend the curing time to 8-10 minutes.

[0034] S104: Set a first hemispherical mold that matches the target first hemispherical printing film, and set a second hemispherical mold that matches the target second hemispherical printing film.

[0035] Among them, the target first hemisphere printing film corresponds to the first hemisphere mold, and the target second hemisphere printing film corresponds to the second hemisphere mold. That is, a first hemisphere mold that matches the target first hemisphere printing film can be set, and a second hemisphere mold that matches the target second hemisphere printing film can be set.

[0036] S105: Place the target first hemisphere printed film into the first hemisphere mold.

[0037] In this process, the target first hemisphere printing film can be placed into the first hemisphere mold first, so that the transfer of the first hemisphere image and text can be completed based on the first hemisphere mold and the target first hemisphere printing film.

[0038] S106: Inflate the PVC inflatable balloon blank to a first preset diameter, place the PVC inflatable balloon blank inside the target first hemisphere printed film, and then inflate the PVC inflatable balloon blank a second time to make it expand and tightly adhere to the first inner wall of the target first hemisphere printed film.

[0039] In this process, a PVC inflatable ball blank can be inflated to a diameter slightly smaller than the inner diameter of the first hemispherical mold. Then, the ball blank is placed inside the first hemispherical printing film and inflated a second time to make the ball blank expand and fit tightly against the inner wall of the first hemispherical printing film.

[0040] Here, "slightly smaller than" can be understood as the diameter of the spherical blank after inflation being 3%-10% smaller than the inner diameter of the corresponding mold. For example, if the first preset diameter is d1 and the first inner diameter of the first hemispherical mold is s1, then (s1-d1) / s1 is within 3%-10%.

[0041] The PVC inflatable ball can be a soft PVC ball made using a slush molding process, unlike a beach ball. It can be an inflatable ball welded from PVC sheets. In this embodiment, the PVC inflatable ball is made by rotational molding PVC paste resin in a mold at high temperature, possessing rubber-like properties and pressure resistance. Inflation requires an air pump. This type of PVC inflatable ball is a mixture of PVC and a high content of plasticizers, such as dibutyl phthalate. Such high-content PVC inflatable balls are characterized by their surface being particularly difficult to adhere. In this embodiment, it is generally difficult to achieve precise adhesion and transfer of the graphic ink layer to the surface of the PVC inflatable ball using ordinary glue.

[0042] Optionally, the PVC inflatable balloon blank is a PVC inflatable balloon blank whose surface has undergone coating pretreatment.

[0043] The PVC inflatable ball blank can be a PVC inflatable ball blank with a pre-coated surface. Specifically, a PVC inflatable ball blank is provided first, and then the surface of the PVC inflatable ball blank is pre-coated to significantly improve the adhesion between the PVC substrate and subsequent coatings (such as paint, ink, adhesives, etc.), which helps to improve the surface printing effect of the PVC rubber inflatable ball.

[0044] Optionally, the coating pretreatment uses a special PVC surface treatment agent for coating.

[0045] The PVC inflatable ball blank is pre-treated with a special PVC surface treatment agent, or a special PVC treatment liquid can be used. After natural drying, subsequent steps can be carried out. This can significantly improve the adhesion between the PVC substrate and subsequent coatings (such as paint, ink, adhesives, etc.), and help improve the surface printing effect of the PVC rubber inflatable ball.

[0046] For example, in the specific implementation, the surface of the PVC inflatable ball can be pretreated first. Specifically, a PVC-specific adhesive can be diluted with a solvent (such as ethyl acetate) and then sprayed or flow-coated onto the surface of the PVC inflatable ball. This creates a dense coating L on the surface of the PVC inflatable ball. This coating has a strong inward adhesion to the PVC inflatable ball, and most importantly, it can prevent the plasticizer of the PVC inflatable ball from migrating outward, blocking the outward penetration of the plasticizer and improving the surface adhesion, so that many adhesives can bond with this layer.

[0047] Furthermore, since the embodiment of this application involves an inflatable ball, which has good elasticity, the adhesive for bonding the printed ink graphic layer must also be elastic and flexible. In this embodiment, a two-component elastic modified adhesive P, such as a two-component silicone, polyurethane, or other elastic adhesive, can be used to bond the coating inward and the printed ink graphic layer outward.

[0048] Optionally, the first preset diameter is smaller than the first inner diameter of the first hemispherical mold, and the ratio between the first preset diameter and the first inner diameter is within a first preset range.

[0049] The first preset range can be preset or set by system default, and the first preset diameter is smaller than the first inner diameter of the first hemispherical mold. For example, if the first preset diameter is d1 and the first inner diameter of the first hemispherical mold is s1, such that d1 / s1 is within the first preset range, for example, d1 / s1 is 92%~98%.

[0050] S107: After the adhesive is kept in place on the first inner wall for a first preset time and the glue is cured, the target first hemispherical printed film is peeled off from the surface of the PVC inflatable ball blank to obtain the target PVC inflatable ball blank.

[0051] The target PVC inflatable ball blank is a PVC inflatable ball blank on which the first hemisphere graphic has been transferred onto its surface.

[0052] Specifically, the target first hemisphere printed film can be left to stand on the first inner wall in an adhered state for a first preset time to allow the adhesive to cure. After the adhesive has cured, the target first hemisphere printed film is peeled off from the surface of the PVC inflatable ball blank to obtain the target PVC inflatable ball blank. The target first hemisphere printed film is then left to stand in an adhered state for a period of time to allow the adhesive to cure. After this time, the target first hemisphere printed film is peeled off from the surface of the ball blank. At this point, the transfer of the first hemisphere graphic on the surface of the PVC inflatable ball blank is complete.

[0053] Optionally, the first preset duration is within a first preset time range.

[0054] The first preset duration can be within a first preset time range, which can be preset or defaulted to by the system. For example, the first preset time range is 2 minutes to 8 minutes, or 3 minutes to 6 minutes, or 3 minutes to 10 minutes.

[0055] S108: Place the target second hemisphere printed film inside the second hemisphere mold.

[0056] In this process, the target second hemisphere printing film can be placed into the second hemisphere mold first, so that the transfer of the second hemisphere graphics and text can be completed based on the second hemisphere mold and the target second hemisphere printing film.

[0057] S109: Inflate the target PVC inflatable blank to the second preset diameter, and transfer the target PVC inflatable blank into the second hemispherical mold so that it is located inside the target second hemispherical printing film. Perform secondary inflation so that the target PVC inflatable blank expands and tightly adheres to the second inner wall of the target second hemispherical printing film.

[0058] In this process, the PVC inflatable ball blank that has already completed the first hemisphere graphic transfer can be inflated to a diameter slightly smaller than the inner diameter of the second hemisphere mold. Then, the ball blank is transferred into the second hemisphere mold, so that it is located inside the second hemisphere printing film, and is inflated a second time, so that the ball blank expands and fits tightly against the inner wall of the second hemisphere printing film.

[0059] Here, "slightly smaller than" can be understood as the diameter of the spherical blank after inflation being 3%-10% smaller than the inner diameter of the corresponding mold. For example, if the second preset diameter is d2 and the second inner diameter of the second hemisphere mold is s2, then (s2-d2) / s2 is within 3%-10%.

[0060] Optionally, the second preset diameter is smaller than the second inner diameter of the second hemispherical mold, and the ratio between the second preset diameter and the second inner diameter is within a second preset range.

[0061] The second preset range can be preset or set by system default. The second preset diameter is smaller than the second inner diameter of the second hemispherical mold. For example, if the second preset diameter is d2 and the second inner diameter of the second hemispherical mold is s2, such that d2 / s2 is within the first preset range, for example, d2 / s2 is 92%~98%.

[0062] Optionally, the first preset diameter can be the same as or different from the second preset diameter.

[0063] Wherein, the first preset diameter is the same as the second preset diameter, or the first preset diameter is different from the second preset diameter.

[0064] S110: After the adhesive is kept in place on the second inner wall for a second preset time, the target second hemisphere printing film is peeled off from the surface of the target PVC inflatable ball blank to obtain the transfer of all the graphics on the surface of the PVC rubber ball blank.

[0065] In this process, the second inner wall is kept in a bonded state and left to stand for a period of time until the adhesive cures. Then, the printed film on the target second hemisphere is peeled off, completing the transfer of all the graphics and text onto the surface of the PVC rubber ball blank.

[0066] Optionally, the second preset duration is within a second preset time range.

[0067] The second preset duration can be within a second preset time range, which can be preset or set by default. For example, the second preset time range is 2 minutes to 8 minutes, or 3 minutes to 6 minutes, or 3 minutes to 10 minutes.

[0068] Among them, such as Figure 2 As shown, a PVC inflatable ball may include an air nozzle, through which the PVC inflatable ball can be inflated.

[0069] Among them, such as Figure 3 As shown, a PVC inflatable ball can include two hemispheres, for example, the Southern Hemisphere and the Northern Hemisphere, such as... Figure 4 As shown, further examples include "Southern Hemisphere" which can correspond to "First Hemisphere Printed Film" and "Northern Hemisphere" which can correspond to "Second Hemisphere Printed Film". For instance, "Northern Hemisphere" can correspond to "First Hemisphere Printed Film" and "Southern Hemisphere" can correspond to "Second Hemisphere Printed Film".

[0070] Among them, such as Figure 5 As shown, the first hemispherical printing film can correspond to the first hemispherical mold, and the second hemispherical printing film can correspond to the second hemispherical mold.

[0071] Among them, such as Figure 6 As shown, the target first hemisphere printed film is placed into the first hemisphere mold, and then the PVC inflatable balloon blank is placed inside the target first hemisphere printed film.

[0072] Among them, such as Figure 7 As shown, within the first hemispherical mold, a PVC inflatable balloon blank can be inflated a second time, causing it to expand and fit tightly against the first inner wall of the target first hemispherical printing film, thereby completing the transfer of the first hemispherical image and text.

[0073] Among them, such as Figure 8As shown, the PVC inflatable blank that has been transferred by the first hemisphere mold is inverted so that the second hemisphere is aligned with the second hemisphere mold. Inside the second hemisphere mold, the target PVC inflatable blank can be expanded and tightly adhered to the second inner wall of the target second hemisphere printed film.

[0074] For example, "first hemisphere" refers to the Southern Hemisphere and "second hemisphere" refers to the Northern Hemisphere. In practice, the Southern Hemisphere graphics can be printed first (steps S105-S107), followed by the Northern Hemisphere graphics (steps S108-S110). The Northern Hemisphere graphics should overlap the Southern Hemisphere graphics by 0.2mm. If both hemispheres are printed simultaneously, a seam will inevitably appear. Printing the Southern Hemisphere graphics first and then the Northern Hemisphere graphics can avoid this seam.

[0075] In related technologies, spherical transfer printing typically involves transferring both hemispheres simultaneously. This method is efficient and ensures accurate alignment, but it has a fatal flaw: a seam appears at the junction of the two hemispheres, which is unsightly. This application provides a solution for a slight overlap between the first and second hemisphere graphics. For example, in this embodiment, the graphics are first designed, with either the first or second hemisphere graphics slightly exceeding the first hemisphere's radius. At least one hemisphere's graphics are more than half the original radius. For instance, the first hemisphere's graphics might be exactly at the radius, while the second hemisphere's graphics exceed the radius, or vice versa. Then, the first hemisphere is printed first, with adhesive applied inside. A PVC inflatable ball with an L-layer (i.e., pre-treated by coating the surface of the inflatable ball blank with a special PVC surface treatment agent) is placed in the hemisphere transfer mold at a diameter smaller than the mold diameter. After inflation, the PVC ball with the L-layer overlaps with the ball coated with elastic adhesive. The first hemisphere is brought into close contact and a certain pressure and time are maintained. The substrate shell of the first hemisphere is then peeled off to complete the transfer. Next, the PVC sphere of the first hemisphere is deflated so that it is smaller than its diameter. Then it is placed into the transfer mold of the second hemisphere, with the image of the second hemisphere slightly higher than the radius (0.01mm~2mm). Similarly, it is inflated to ensure that L and P are tightly bonded. After the mold is closed, it is inflated and pressurized. Furthermore, the pressure is maintained for a certain time. If it is fast, a slight temperature can be added (e.g., 20℃~50℃). Then the pressure is released, and the transfer shell of the second hemisphere is peeled off. Finally, the image of the second hemisphere overlaps the image of the first hemisphere, with an overlap of 0.05mm~1mm.

[0076] For example, Figure 9As shown, Figure a shows the transfer effect of the first hemisphere after being transferred to the first hemisphere mold, corresponding to the first graphic line and the transferred content of the first hemisphere. For example, the area below the first graphic line is the graphic content corresponding to the first hemisphere. Figure b shows the transfer effect of the first hemisphere transferred onto the inverted PVC inflatable blank to facilitate better transfer of the second hemisphere. Figure c shows the transfer effect of the inverted PVC inflatable blank after being transferred into the second hemisphere mold, i.e., the transfer effect after the second hemisphere has also been transferred. Specifically, the upper area of ​​Figure c is the transferred content of the first hemisphere, corresponding to the first graphic line, and the lower area of ​​Figure c is the transferred content of the second hemisphere, corresponding to the second graphic line. At this time, the first graphic line is located below the second graphic line, and the distance between the first and second graphic lines is the overlapping range corresponding to the overlap. Further, as... Figure 10 As shown, in order to better present the overlapping effect, the graphic content has been simplified. It can be seen that the upper area is the transfer content area of ​​the first hemisphere, which corresponds to the first graphic line, and the lower area is the transfer content area of ​​the second hemisphere, which corresponds to the second graphic line. The distance between the first graphic line and the second graphic line is the overlapping range corresponding to the overlapping.

[0077] As can be seen, in this embodiment, a pre-designed graphic is reverse-printed onto a thermoplastic plastic transfer film to obtain a target plastic transfer film. A first hemispherical printing film and a second hemispherical printing film are then generated based on the target plastic transfer film. Adhesive is applied to the inner surfaces of the first and second hemispherical printing films respectively to obtain a target first hemispherical printing film and a target second hemispherical printing film. A first hemispherical mold matching the target first hemispherical printing film and a second hemispherical mold matching the target second hemispherical printing film are set up. The target first hemispherical printing film is placed into the first hemispherical mold. A PVC inflatable balloon blank is inflated to a first pre-set diameter and placed inside the target first hemispherical printing film. The PVC inflatable balloon blank is then inflated a second time to expand and tightly adhere to the first inner wall of the target first hemispherical printing film. The film remains in this adhered state on the first inner wall for a first pre-set time until the adhesive cures. The target first hemisphere printed film is peeled off from the surface of the PVC inflatable ball blank to obtain the target PVC inflatable ball blank. The target second hemisphere printed film is placed in the second hemisphere mold. The target PVC inflatable ball blank is inflated to a second preset diameter and then transferred into the second hemisphere mold, so that it is located inside the target second hemisphere printed film. A second inflation is performed to make the target PVC inflatable ball blank expand and tightly adhere to the second inner wall of the target second hemisphere printed film. The adhered state is maintained on the second inner wall for a second preset time. After the adhesive has cured, the target second hemisphere printed film is peeled off from the surface of the target PVC inflatable ball blank, and the entire graphic is transferred to the surface of the PVC rubber ball blank. By pre-decomposing the preset graphic (the pattern to be printed) into two hemisphere printed films and using matching hemisphere molds for positioning and operation, the complex global surface problem is simplified into two relatively controllable local surface problems. The step-by-step processing (first the first hemisphere, then the second hemisphere) greatly reduces the difficulty of accurately positioning and attaching the pattern on the complete spherical surface in one go. Ultimately, it can achieve high precision, no deformation, no seams, and high accuracy on the entire PVC inflatable ball blank surface, which can improve the surface printing effect of PVC rubber inflatable balls.

[0078] For example, in this embodiment of the application, the surface printing method for a PVC rubber inflatable ball can be performed according to the following steps: a. Pre-treat the surface of the PVC inflatable ball blank with a coating; b. Print the design graphics in reverse onto a thermoplastic transfer film; c. Perform vacuum forming on the plastic transfer film with printed graphics, so that it is deformed into a first hemisphere printing film and a second hemisphere printing film that match the shape of the hemisphere of the balloon to be printed. d. Apply adhesive to the inner surfaces of the first and second hemispherical printed films after vacuum forming; e. Set up a first hemispherical mold that matches the first hemispherical printing film and a second hemispherical mold that matches the second hemispherical printing film respectively; f. Place the first hemispherical printing film coated with glue into the first hemispherical mold; g. Inflate the PVC inflatable ball blank after step a to a diameter slightly smaller than the inner diameter of the first hemispherical mold, then place the ball blank inside the first hemispherical printing film and inflate it a second time to make the ball blank expand and fit tightly against the inner wall of the first hemispherical printing film. h. Keep the glued state and let it stand for a preset time. After the glue has cured, peel the first hemisphere printing film off the surface of the ball blank. At this time, the transfer of the first hemisphere graphic on the surface of the ball blank is completed. i. Place the second hemisphere printing film coated with glue inside the second hemisphere mold; j. Inflate the PVC inflatable ball blank that has completed the first hemisphere graphic transfer to a diameter slightly smaller than the inner diameter of the second hemisphere mold. Then transfer the ball blank into the second hemisphere mold so that it is located inside the second hemisphere printing film. Perform a second inflation to make the ball blank expand and fit tightly against the inner wall of the second hemisphere printing film. k. Keep the glued parts in place for the preset time. After the glue has cured, peel off the second hemisphere printing film to complete the transfer of all the graphics and text onto the surface of the PVC rubber ball blank.

[0079] In this example, the preset graphic (the pattern to be printed) can be pre-decomposed into two hemispherical printing films, and each film can be positioned and manipulated using a matching hemispherical mold. This simplifies the complex global surface problem into two relatively controllable local surface problems. The step-by-step processing (first the first hemisphere, then the second hemisphere) greatly reduces the difficulty of accurately positioning and attaching the pattern on the complete spherical surface in one go. Ultimately, it can achieve high precision, no deformation, no seams, and high accuracy on the entire surface of the PVC inflatable ball blank, thus improving the surface printing effect of the PVC rubber inflatable ball.

[0080] To illustrate further, in this embodiment of the application, the surface printing method for a PVC rubber inflatable ball can be performed according to the following steps: A blank PVC balloon with a diameter of 32cm can be selected as the substrate. First, the surface of the balloon blank is coated to improve the surface dyne value. Then, a PVC plastic film is selected as the transfer substrate. The design graphics are reverse-printed onto the PVC film using a gravure printing machine. The printed PVC film is placed on a vacuum forming machine and heated to 90°C. It is then vacuum-formed into two hemispherical shells, namely the first hemispherical printing film and the second hemispherical printing film, through a mold. Polyurethane adhesive is evenly coated on the inner sides of the two hemispherical films. Finally, the first hemispherical printing film is placed into the first hemispherical mold (with an inner diameter of 3cm). Next, inflate the sphere to a diameter of 30cm and place it in the first hemisphere mold. After aligning it, inflate it a second time to expand the sphere to a diameter of 32cm, ensuring it adheres tightly to the first hemisphere printing film. Hold the pressure and let it stand for 5 minutes until the adhesive has initially cured. Then, remove the sphere and peel off the first hemisphere printing film. At this point, the surface of the sphere will have the first hemisphere pattern printed on it. Place the second hemisphere printing film into the second hemisphere mold (inner diameter 32cm). Inflate the sphere with half of the pattern printed on it to a diameter of 30cm and place it in the second hemisphere mold. Inflate it a second time to a diameter of 32cm, ensuring the sphere adheres tightly to the second hemisphere printing film. Hold the pressure and let it stand for 5 minutes. Remove and peel off the second hemisphere printing film to obtain a finished sphere with complete graphics and text.

[0081] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A method for surface printing on a PVC rubber inflatable ball, characterized in that, The method includes: The pre-designed graphics are reverse-printed onto a thermoplastic plastic transfer film to obtain the target plastic transfer film. A first hemispherical printing film and a second hemispherical printing film are generated based on the target plastic transfer film; Adhesive is applied to the inner surfaces of the first hemispherical printed film and the second hemispherical printed film respectively to obtain the target first hemispherical printed film and the target second hemispherical printed film. A first hemispherical mold matching the target first hemispherical printing film is provided, and a second hemispherical mold matching the target second hemispherical printing film is provided; The target first hemisphere printed film is placed into the first hemisphere mold; Inflate the PVC inflatable balloon to a first preset diameter, place the PVC inflatable balloon inside the target first hemisphere printed film, and then inflate the PVC inflatable balloon a second time to make it expand and fit tightly against the first inner wall of the target first hemisphere printed film. The target first hemisphere printed film is peeled off from the surface of the PVC inflatable ball blank after the adhesive has cured and the glue remains in a fixed position on the first inner wall for a first preset time. Place the target second hemisphere printed film inside the second hemisphere mold; The target PVC inflatable blank is inflated to the second preset diameter, and then the target PVC inflatable blank is transferred into the second hemispherical mold, so that it is located inside the target second hemispherical printing film. It is then inflated a second time, so that the target PVC inflatable blank expands and fits tightly against the second inner wall of the target second hemispherical printing film. After the adhesive has cured, the target second hemisphere printing film is peeled off from the surface of the target PVC inflatable ball blank, thus obtaining a transfer of all the graphics and text onto the surface of the PVC rubber ball blank.

2. The surface printing method for PVC rubber inflatable balls according to claim 1, characterized in that, The PVC inflatable balloon blank is a PVC inflatable balloon blank whose surface has undergone coating pretreatment.

3. The surface printing method for PVC rubber inflatable balls according to claim 2, characterized in that, The coating pretreatment uses a special PVC surface treatment agent for coating.

4. The surface printing method for PVC rubber inflatable balls according to any one of claims 1-3, characterized in that, The step of generating a first hemispherical printing film and a second hemispherical printing film based on the target plastic transfer film includes: The target plastic transfer film is subjected to vacuum forming to deform it into a first hemispherical printing film and a second hemispherical printing film that match the preset hemispherical shape of the balloon to be printed.

5. The surface printing method for PVC rubber inflatable balls according to claim 4, characterized in that, The vacuum forming temperature is controlled between 80℃ and 150℃.

6. The surface printing method for a PVC rubber inflatable ball according to any one of claims 1-3, characterized in that, The first preset diameter is smaller than the first inner diameter of the first hemispherical mold, and the ratio between the first preset diameter and the first inner diameter is within a first preset range.

7. The surface printing method for PVC rubber inflatable balls according to any one of claims 1-3, characterized in that, The second preset diameter is smaller than the second inner diameter of the second hemispherical mold, and the ratio between the second preset diameter and the second inner diameter is within a second preset range.

8. The surface printing method for a PVC rubber inflatable ball according to any one of claims 1-3, characterized in that, The first preset duration is within the first preset time range.

9. The surface printing method for a PVC rubber inflatable ball according to any one of claims 1-3, characterized in that, The second preset duration is within the second preset time range.

10. The surface printing method for a PVC rubber inflatable ball according to any one of claims 1-3, characterized in that, The first preset diameter is the same as, or different from, the second preset diameter.

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